Family-friendly filters will soon be automatically installed when most new subscribers sign up for Internet service, with customers wishing to view pornography needing to make a conscious choice to turn them off. Before the end of next year, most of the 21 million wired households in Britain will also be placed in the awkward position of having to declare whether they want to keep access to legal online pornography or have it blocked by their telecommunications providers.
Cameron is also demanding that search engines such as Google and Yahoo create a "blacklist" of terms relating to child pornography that, when strung together, come back with no hits. His government is also moving to ban the possession of a broader range of images, including not only child pornography but also images depicting consenting adults engaged in violent acts such as simulated rape.
"We now have the ambition to make Britain the most family-friendly democracy in the world," said Claire Perry, a member of Parliament from Cameron's Conservative Party and his point person in the anti-pornography push.
Free-speech advocates, however, see a slippery slope one that could eventually rob Britain of the moral authority to denounce government-imposed Internet filtration in countries such as China. Perhaps more than any other Western nation, critics say, Britain has become a test case for how and whether to more deeply police Internet images and social media in free societies.
Several Western nations already have limited policing of the Internet. Germany has long banned online material that, for instance, denies the Holocaust.
But Britain is putting in place some policies that could result in a broader filtration of material from public view. For instance, after a British soldier was killed in a gruesome knife attack on a London street, allegedly by Islamist extremists, Britain's Home Office created a task force to look at whether the government should do more to compel search engines to block extremist material religious or political that incites violence and indoctrinates youth.
Next month, executives from Google, Facebook, Twitter and other technology companies will be asked to appear at a parliamentary hearing in London on Internet security and safety with British lawmakers studying the possibility of fresh guidelines or new legislation to combat everything from cyber-bullying to the ability of children to view explicit material online.
Critics say that by moving to expand the definition of illegal pornographic images to include so-called "rape porn," the government will be creating a subjective system where empowered "censors" become the arbitrators of good taste. And in a world of increasingly risqué mainstream material HBO's hit "Game of Thrones," for instance, depicts graphic sexual violence against women free-speech advocates wonder where the lines may ultimately be drawn.
Meanwhile, rolling out Internet filter systems to such a large portion of British households, some argue, could easily create a tool for blocking other types of objectionable material. The British court system, for instance, has already begun tapping into such systems to demand the blocking of websites that infringe on copyrighted material.
"They wanted to block extreme pornography, and I said nothing, then they wanted to block material that infringed on copyrights, and I said nothing, and then they started to block websites with extreme messages that didn't quite agree with the government line, and I still said nothing," said Alex Bloor, business development manager at Andrews & Arnold, a British Internet service provider popular with computer savvy subscribers. "This is the thin end of a massive wedge."